Under the law, insurance companies — and health care providers ... must comply with new requirements to keep directories updated at least every quarter.

The law, which took effect July 1, also provides patients with some firepower to fight surprise medical bills that result from directory errors.

The law’s reach is broad: It applies to Covered California and private market plans, as well as Medi-Cal managed care and most job-based insurance policies.

The inaccuracy of directories, Hernandez says, “has been and … seems to continue to be a problem that needs to be rectified.”

Several other states, from Georgia to Maryland, have passed similar legislation or are considering doing so, says Claire McAndrew, private insurance program director for Families USA, a national health care consumer advocacy group. In some states, insurance commissioners have adopted new rules through the regulatory process.

But California’s law “is the most comprehensive,” she says. “The level of detail in California goes beyond any other state.” Federal officials also instituted a rule this year requiring directories be updated monthly for all plans sold on the 37 state marketplaces run by the federal government.

And they set new rules for Medicare Advantage plans, requiring that the companies contact doctors every three months and update their online directories within 30 days. A recent study in the journal Health Affairs found that provider directories for some health plans sold through Covered California and in the private market are so inaccurate that they create a “disheartening” situation for consumers trying to find doctors.

That finding was confirmed this month when the state Department of Managed Health Care (DMHC) announced that Anthem Blue Cross and Blue Shield of California — which were previously fined for inaccuracies in their Covered California provider directories — still had “disappointing” directory problems.

“We are optimistic and hopeful that the law … will help,” says department director Shelley Rouillard.

Among the law’s new rules:

Health plans must update their printed directories at least every quarter and their online directories at least every week if providers report changes.

Provider directories must be posted online and be available to anyone, not just enrollees. Print directories must be available upon request.

The directories must “prominently” display directions for consumers who want to report inaccuracies. Upon receiving complaints, plans have 30 business days to makes changes, if necessary.

Providers must inform plans within five business days if they are no longer accepting new patients — or, alternately, if they will start accepting them.

Health plans can delay payments to providers who fail to respond to attempts to verify information.

The California law also gives consumers recourse. Let’s say you use a provider directory to find a doctor but you’re billed the out-of-network price because the directory was wrong. In that case, health plans must reimburse you the amount beyond what you would have paid to see an in-network doctor.

If you find yourself in this situation, first take your complaint to your plan, advises DMHC’s Rouillard. You will have at least 180 days from the date you received the bill to file a grievance. ...